Track roller for tractors



Sept. 1925.

T. C. LEAKE TRACK ROLLER FOR THACTORS Filed May 22, 1923 2 Sheets--Shaet l INVENTOR ATTORNEY 2 Sheets-Sheet 2 Will! 4 r M lag/J2 w/W ATTORNEY "5" 53 LEAKE TRACK ROLLER FOR TRACTORS Filed May 2 1923 Patented Sept. 7, 1926.

UNITED STATES THOMAS C. LEAKE, OF NEW YORK, N. Y}, ASSIGNOR TO BEAR TRACTOR CORPORATION OF AMERICA, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

TRACK ROLLER FOR. TRACTORS.

Application filed May 22,

a traction tread.

it is a general object of the invention to provide an improved support for the flexible traction element of tractors or the like, whereby that'element is held in contact with the ground, and to maintain effectively its traction and supporting engagement there with over rough or irregular surfaces.

A further object of the invention is the provision of an improved articulated rollerconstruction for supporting flexible traction elen'ients of tractors or the like, so as to effec-' tively equalize and distribute the loads transmitted thereto.

Still another object is to provide a simple and reliable equalizing track supporting roller construction for tractors or the like, with an improved mechanism for absorbing thrusts and stresses incident to use.

Other objects will be in part obvious in connection with the following detailed description of illustrative embodiments of the invention, and will be in part pointed out in connection therewith.

The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts, which will be exemplified in the construction herein after set forth and the scope of the application of which will be indicated in the claims.

For a complete understanding of the nature and objects of the invention, reference is had to the following detailed description, and to the accompanying drawings in which Fig. 1 is a side elevation of a tractor construction embodying the invention,

Fig. 2 is an enlarged fragmentary elevation of the track roller construction,

Fig. 3 is an enlarged sectional view taken approximately on the line 3-3 of Fig. 2, looking in the direction of the arrow, and

Fig. at is a side elevation corresponding to Fig. 2, but showing a modified form of the invention.

Referring to the accompanying drawings for a detailed description of the embodiments of the invention there shown, and first to the modification shown in Figs. 1 to 8 inelusive, a tractor of the flexible tread type 1923. Serial No: 640,662.

is shown in a somewhat fragmentary manner, only enough of the general construction of the tractor being shown to make clear the application and operation of the improvements. A side or track frame of the tractor is indicated at 10, having inner and outer spaced frame members or sills 11 and 12,and track supporting sprockets 13 and 14 are spaced therealong. Power is ordinarily supplied to the flexible tread or track 15 through the rear or driving sprocket 13, and the front or idler sprocket 14 is preferably mounted on the tractor frame 10 and carries the front part of the flexible traction element around which the latter extends. A hearing carried by an adjustable bracket 16 is employed for supporting the idler sprocket and an adjusting mechanism 17 mounted on the track frame 10 is preferably employed for convenient adjustment of the idler sprocket to vary the tension of the flexible traction tread.

For supporting the reach of the flexible tread between front and rear sprockets, a track supporting roller construction is provided, which in the embodiment shown includes a series of three track engaging rollers 18, 19 and 20 adapted for engagement with the inner face ofthe track links, or with suitable rails carried thereby. The rollers are rotatably mounted on equalizing or compensating bars or levers 21 and 22 which are preferably arranged in forward and rearward pairs and between which the-rollers are positioned. The forward and rearward equalizing levers are pivoted together at their adjacent ends as at 23 preferably coincident with the axis and forming the spindle of the intermediate roller 19, while the rollers 18 and 20 are connected respectively at far ends of the equalizing bars 21 and 22 as by spindles 2st and 25. stood that a greater or less number of rollers may be employed dependent upon length of track span to be supported, operating conditions and other factors.

Each of the equalizing levers 21 and 22 is yieldably connected to the track frame of the tractor by a spring box arrangement, which is substantially the same forboth levers, and a detailed description of one will therefore suffice for both. As shown in Figs. 2 and 3 the spring box construction includes a housing 26, preferably'of cast metal disposed between and connected to the frame It will be under-- extend below the sills 11 and 12, forming lateral guides for the up and down move-i ment of the spring block 27 and being reenforced by'exterior brackets 28 riveted to the tractor frame. A? Opposite lateral sides the spring block 2? is provided with lugs 29, spaced inwardly from the walls and adapted for the attachment of the equalize ing bars 2l'or 22. As shown in Fig.- 3,each equaliz ng bar is pivoted ntermediate its ends to the spring block by meil li of pins 30 extending through the walls "of' the box and into the adjusting lugs 29. For yieldingly supporting the spring blocku27 for up and down movement relative to the tractor frame, a spring 31is interposed between the spring block and the upper spring plate 32,

forming a seat for the spring and being adjustable by means of a screw 33 mounted in the housing 26. As shown, a plurality of concentric spiral springs are preferably provided for this purpose, the tension being ad} justed by means of the adjusting screw 33 in' accordance with the requirementsof the service in which the tractor is employed.

It will be understood that undue lateral movement of the track rollers transversely of the tractor will be prev n sil'bt weesment of the spring blocks 27, with the adia cent walls of the housing 26, but longitudinal movement thereof is resisted by means'of a construction which will now be described.

Connected to an end of; the equalizing links, such as to the link 22 as shown in Fig.

i 2, is a cross link 34. Link 34 is connected intermediate its ends preferably coincidentally with the pivotpin'25, and attheupper end thereof a linker radius rod 35 ispivoted. At its forward end the radius rod 35 is pive oted to a bracket 36 secured to the tractor.

frame 10 in any desired manner. To the lower end of the cross link 34; a second or rearwardly extending radius rod ispivoted, the rear end of this 'rod being pivoted as at 38 to the downwardly extending bracket 28. It. will be understood that this radius rod construction which is adapted to take up the longitudinal thrust upon the track rollers may be duplicated at oppositesides of the track rollers as shown in the drawing, or it may be omitted either. at the inner or outer side of the rollers.

In operation by means of the construction above described, it'will be seen that upward thrusts upon any one of the track rollers, not only will be. transmitted to, the tractor frame through the springconnections described, but suchthrusts will also be trans mitted through the respective equalizing bars to the adjacent rollers and through the rollers to or from the flexible traction tread. The connection o he ro l r o h eq lizing bars and the connections, of the bars to the spring blocks are so spaced relatively to each other and inter-arranged that the flexible; tread is effectively 7 supported in engagement with the ground and good tractive Contact is thus maintained even over very rough I and irregular surfaces.

Also Wear and strain on the track links and u on the roller construction itself are reduced due to the resilient connection of the rollers to the tractor frame and particularly because of the equalizing connections .ofthe rollers whereby the stresses and loadstransmitted therethrough are equalized and d st ibut d. ove a g par of he stretch of t ea ext nd ng bet emai supporting sprockets, The relative arrangement and spacing of the roller bearings and equalizer bar'supports as illustrated in the drawing, that is, with the equalizer bars fulcrumed as at 30 at about one-third ofthe distances from the outer ends thereof, is found effective for proper distribution of the load stresses. Side thrusts upon theirolL ers before stated, are taken up 'bythe lateral Walls of the housing 26, but longitudi- Ila-. thru ereon. ill b retfe t y sorbed by the radius links or rods 35, and 3.7;. This arrangement permits'free upward and downward movement of the rollers withou binding, thus redu ng ear n the p but undue longitudinal movement of the track roller construction will be provi'ded'by operation of these radius rods. It will be seen that the cross link 34; connected as describedfunctions as an equalizer for 'articu lating theradius rods 35 and with the equalizino: bar'22 so as to equalize transmitted thrusts and to compensate for up and down movement of said equalizing bar 22.

In the modification of Fig. 4 the general assembly and arrangement of parts are si nilarto that disclosed in the modification previously described and the corresponding parts are designated by similar reference numerals with the index a. The front or idler sprocket is indicated at 14? and the threerollers at 18?, 19 and 20 respectively, the latter-being interconnected as before by th q li er ba s 21 an 22* w i were? siliently supported intermediate their ends upon the tractor framethrough the spring cks 2 i Infthis modification however, each of the radius rods as indicated at 40 is pivoted (ll? rectly to the forward end of the correspond" ing forwardequalizing bar 22, preferably coincident with the axis 25 of the'forward track roller 20. The forward end of this equalizer bar is pivoted to a bracket tl, preferably an integral casting riveted to' the tractor frame This braclzet 41 preferably extends above the upper surfaces of the frame forming a bearing 42 for the forward end of the adjusting mechanism 17 for the idler sprocket As in the modification previously described, it will be understood that the equalizing bars may bearranged in pairs disposed on opposite sides of the track rollers, and the radius rods are preferably arranged in corresponding pairs connected to the forward ends of the forward equalizing bars 22.

The ope *ation of this form of the inven tion is similar to that above described, and will be obvious without reiteration. The construction in this case, however, is somewhat simpler and the number ofparts reduced resulting in advantages from manufacturing and operating standpoint-s.

Since certain changes may be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is

1. In a tractor, in combination, a frame for the tractor, wheels mounted on said frame, an endless flexible traction tread carried by said wheels, a plurality of track rollers for supporting a. reach of said tread intermediate said wheels, articulated equalizing bars upon which said rollers are rotatably mounted in. spaced relation, one of said rollers being mounted at the articulation point of said equalizing bars, means for pivotally mounting said equalizing bars in termediate their ends on the tractor frame, and a rod operatively connected to one of said equalizing bars adjacent the end there of remote from said articulation point and anchored to the tractor frame to absorb end thrusts upon said rollers.

2. In a tractor, in combination, a frame for the tractor, wheels mounted on said frame, an endless flexible traction tread mounted upon said wheels, a plurality of tracl; rollers for supporting a reach of said tread intermediate said wheels, articulated equalizing bars upon which said rollers are rotatably mounted, spaced supporting blocks yieldingly carried by the tractor frame to each of which one of said equalizing bars is connected for pivotal movement and a radius rod operatively connected to one of said equalizing bars and anchored to the tractor frame to absorb end thrusts upon said rollers.

3. In a tractor in combination, a frame for the tractor, wheels mounted upon said nected to one of said equalizing bars and anchored to the track frame so as to absorb longitudinal thrusts on said rollers or equalizing bars.

4. In a tractor, in combination, a frame for the tractor, wheels mounted upon said frame, an endless flexible traction tread mounted upon said wheels, a plurality of track rollers adapted toengage a reach of said tread, equalizing bars interconnecting said rollers, spaced supporting blocks yieldingly carried by the tractor frame to each of which one of said equalizing bars is connected for pivotal movement, brackets car ried by the said frame for limiting said equalizing bars and rollers from excessive movement laterally of said flexible tread but permitting free movement thereof longitudinally of said tread, and a radius rod operatively connected to one of said equalizing bars and anchored to the tractor frame.

5. In a tractor, in combination, Wheels mounted upon the tractor, an endless traction tread mounted upon said wheels, a plurality of track rollers for supporting a reach of said tread intermediate said wheels, equalizing bars yieldingly' supported intermediate their ends on the tractor and pivotally connected together at their adjacent ends, said rollers being rotatably mounted in spaced relation upon said equalizing bars I and one of said rollers being mounted at the pivotal connection between said bars, brackets carried by said tractor for confining said equalizing bars and rollers from eX- cessive movement laterally of said flexible tread but permitting free movement thereof longitudinally of said tread, and a radius rod operatively connected to one of said equalizing bars adjacent the end thereof remote from said pivotal connection and anchored to the tractor frame.

6. In a tractor in combination, wheels mounted upon the tractor, an endless flexible traction tread mounted upon said wheels, a plurality of track rollers adapted to enand support a. reach of said tread, equalizing bars interconnecting said rollers, a link connected intermediate its ends to one of said 7. In a tractorin oombinationfa frame for the tractor, Wheels mounted upon said frame, an endless flexible traction tread mounted upon said Wheels, a plurality of rollers adapted to, engage and support a reach of saidtread, equalizing bars. intereonnecting said rollers and heingoonneeted in pairs thereto, movable supporting members; yieldingly carried by said frame toeachof which a pair of said equalizing-bars isoonnected for pivotal movement at spaced parts thereof and intermediate the ends of the. links, guides carried by the frame for guiding movement. of said rollers in a vertical plane but permitting longitudinal movement thereof, and a radius trod operatively attaehed to. one of said equalizinghars and. anchored to. the frame 8.. In a tractor in combination, a frame for the tractor, wheels mounted upon said trainee, an endless. -flexible traction tread mounted upon said wheels, a. plurality of track rolleisadapted toengage. andsupport a reach of said tread, equalizing bars articulated witheach other and upon which said rollers are mounted vsubstantially in longitudinal alignment," supports :for supporting said bars on said frame and including pivotal connections positioned intermediate theends of: eae-hiofa plurality of said equalizing bars, and a plurality of longitudinal thrust absorbing radius .rods havingan equalizing conneetimr with one of said equalizing barsv and anchored to the track frame at. points'ispaoedlongitudinally ther along. a

THOMAS-"C. LEAKE. 

